The present invention is directed to a device for drilling holes into a workpiece which comprises a plate or a stack of plates particularly printed circuit boards and which device includes a drill spindle accepting a drill bit and a clamping arrangement for engaging the workpiece adjacent the location of the hole being drilled and for holding the workpiece during the drilling operation.
Printed circuit boards are provided with through-holes at the respective mounting positions for the acceptance of leads of individual components. The forming of these holes usually occurs by drilling a stack of printed circuit boards. For example, a plurality of printed circuit boards were stacked one on top of another to form a stack and then are drilled so that a single drilling will form the same hole in each board. However, without additional protective measures, ejecta, which makes the respectively topmost printed circuit board unusable, will occur. In order to avoid this, an approximately 0.5 mm thick, special throwaway plate of aluminum or hard paper will usually accompany this stack of printed circuit boards as the topmost layer and is connected to the stack of printed circuit boards at the edges with the assistance of an adhesive tape.
When a batch of the drill devices is to be mechanized, for example, by using industrial robots, the emplacement and gluing of a throwaway plate on a stack of printed circuit boards as well as the undoing of the gluing and removal of the throwaway plate represents additional work steps. These additional work steps will lead to a loss of time and also to a deterioration of the production reliability.